Arsenic in Drinking Water Causes Lung Disease

We typically think a toxic agent has to be inhaled to cause lung disease; think of asbestos or silica, for example. But two new studies by the Arsenic Health Effects Research Program (AHERP) at the University of California Berkeley challenge this thinking. The studies’ findings show that arsenic, a known skin, bladder, and lung carcinogen, can also cause non-cancerous lung disease when swallowed.

In two separate studies to be published this fall, the arsenic research group demonstrates that drinking tube-well water with high concentrations of arsenic was associated with compromised pulmonary function in men and high rates of bronchiectasis – distortion and dilation of the bronchi, which can lead to chronic infections and obstructive lung disease.

The studies were designed by Allan H. Smith, director of AHERP, in collaboration with D. N. Guha Mazumder of the Institute of Post Graduate Medical Education and Research in Kolkata, India. The studies recruited subjects from a rural population in West Bengal, India, which, along with Bangladesh, is home to millions of people exposed to arsenic through drinking water. When ingested over a long period of time, arsenic causes unique skin lesions, giving the researchers a convenient way to identify people who have been exposed to high amounts of the element.

The first publication, whose lead author, Ondine von Ehrenstein, is an environmental epidemiologist at UCB who directs AHERP’s India studies, compared lung function in people with arsenic-caused skin lesions to a matched group with no lesions. Men with lesions and high arsenic exposure had greatly reduced forced expiratory volume in 1 second tests (FEV1) and forced vital capacity (FVC)—measures of the volume of air a person can force out following a deep breath, after one second and in total. This study was funded by the U.S. Environmental Protection Agency and by the National Institute of Environmental Health Sciences (NIEHS) Superfund Basic Research Program at UCB.

In a related study on bronchiectasis, people with skin lesions who had been exposed to drinking water containing high concentrations of arsenic were compared to individuals without skin lesions who had low exposures. The prevalence of bronchiectasis, measured by high resolution computed tomography, was ten times higher in people with skin lesions than in the control group. Craig Steinmaus of AHERP, an assistant professor in occupational and environmental medicine at UCSF, took the lead in analyzing the data and writing up the study, which was funded by the NIEHS Superfund Basic Research Program.

Both studies found that ingested arsenic appears to take a greater toll on the lungs of men than women. Men in the study populations smoked far more than women, but the researchers found that gender differences in arsenic-induced lung disease remained even after ruling out smoking as a complicating factor. Why men would be more susceptible than women remains a mystery.

The installation of tube-wells in India and Bangladesh was undertaken by international aid agencies mainly in the 1970s and 1980s to improve water supplies and to cut down on high rates of diarrheal disease caused by bacterial contamination of drinking water. The wells did help reduce the transmission of gastrointestinal diseases resulting in significant reductions in infant mortality. But because the water in many of them has such high concentrations of arsenic, a whole new set of health risks has been introduced.

Von Ehrenstein and the AHERP team are currently completing another study in West Bengal funded by UNICEF, looking at health effects in women and children who were drinking water with high arsenic concentration in comparison to a group of women and children with low exposure. Among the women she is particularly looking at the impact of exposure during pregnancy. The study is examining reproductive outcomes, like stillbirths and cognitive effects in young children.

Steinmaus, who mainly works on arsenic studies in California and Latin America, is also now looking at the effects of arsenic on children, in Antofagasta, Chile. The parched city drew arsenic-laden drinking water from rivers originating as springs in the Andes mountains from 1958 to 1971, when exposure was reduced through the installation of the first major arsenic removal plant in the world.

Preliminary data from Antofagasta suggest that those who were in utero or young children there in the 1960s have startlingly higher rates of cancer than those in the rest of Chile, or even those who were young adults or older when exposed to the water in Antofagasta. Steinmaus is hoping his future research will elucidate the relationship between age at exposure and risk of disease later in life.